Fully-ambient-processed mesoscopic semitransparent perovskite solar cells by islands-structure-MAPbI3-xClx-NiO composite and Al2O3/NiO interface engineering

Abstract Perovskite solar cells (PSCs) because of low-cost fabrication and high performance have shown superb potential for the next-generation photovoltaic application. For the potential applications of photovoltaic technologies, semitransparent PSCs are also highly attractive and of commercial interest to develop building- and tandem-integrated solar cells. Here, we present fully-ambient-processed stable and mesoscopic semitransparent PSCs by non-continuous islands-structure-CH 3 NH 3 PbI 3-x Cl x -NiO nanoparticles (MAPbI 3-x Cl x -NiO NPs) composite and interface engineering by inserting Al 2 O 3 /NiO between TiO 2 and MAPbI 3-x Cl x -NiO composite layers in a device configuration of FTO/c-TiO 2 /mp-TiO 2 /Al 2 O 3 /NiO/islands-structure-MAPbI 3-x Cl x -NiO /spiro-OMeTAD/Au. Except for the islands-structure-MAPbI 3-x Cl x -NiO capping layer, a uniform and thicker and transparent TiO 2 /Al 2 O 3 /NiO/MAPbI 3-x Cl x composite layer is formed, which can effectively reduce photocurrent density loss and interface recombination. Interestingly, the optimized semitransparent PSCs showed hysteresis-free performance. The average visible transmittance (AVT) of MAPbI 3-x Cl x -NiO NPs composite film was ranged from 18% to 56% and the corresponding device PCE changed from 17.51% to 12.47%. The PSCs without encapsulation showed an excellent air stability over 270 days with retaining ~98% of its original V oc , ~96% of J sc , ~97% of FF and ~93% of PCE under ambient condition (25–30 ℃ and 45–50% humidity). Finally, we achieved semitransparent device of PCE = 10.06%, corresponding to AVT = 27%.